Agricultural square balers gather crop material into a baling chamber where the material is compressed to parallelepiped packages by a reciprocating plunger. The finished packages are tied to form the bales, which proceed to be transported on a guide or slide at the exit of the baler, the so-called bale chute, from which they are lowered to the ground. The bale chute in prior art systems is usually provided with a tilting mechanism to avoid damaging the bales by lowering them gently to the ground. Examples of known balers of this type are described in EP-A-0974260 and EP-A-1935232. In some balers the bales are also weighed before they are discharged. In EP-A-1935232 for example, the bale chute has a rear portion that is pivotable around an axis situated below the bale support surface. The rear portion is further provided with a weighing table supported by load beams configured to produce a weight measurement signal. The baler of EP-A-1935232 may be further provided with a brake to slow down the bales when they are on the weighing table. Such a brake may be a friction brake arranged on a roller when the weighing table is formed of a roller conveyor, or a replaceable friction pad or edge included in the support surface. However, such brake systems are up to now provided as mechanical brakes which are activated manually by the operator. For this reason, the braking action is not always necessary nor can it be adapted to specific conditions in terms of the terrain and the crop. Especially in the case of the baler of EP-A-1935232, because of the specific structure and position of the pivot axis of the weighing table, the bales tend to move under influence of friction and gravity once the centre of gravity of the bale moves past this pivot axis. This movement of the bales is rather uncontrolled and is influenced by local conditions of the crop, the weather and the terrain. This uncontrolled movement leads to random errors when considering the weight measurement signal, which are difficult to compensate in a systematic way. Hence there is a need to have more control over the bale movement from the moment when it is positioned on the weighing table in order to improve the precision of the weighing system.